1. Field of the Invention
The present invention relates to attachment structures for automatic document feeders which feed documents to a predetermined image-reading position, and to image-reading devices and image-forming apparatuses including the attachment structure.
2. Description of the Related Art
Image-forming apparatus can include an automatic document feeder and an image-reading section. A document set on a document tray of the automatic document feeder is fed to an image-reading position, of the image-reading section, and then the image on the document is read.
The automatic document feeder is rotatably supported by one end of an image-forming apparatus body using a hinge unit. A document set on the image-reading section is pressed to the image-reading position by a lower surface of the automatic document feeder. Then, the image surface of the document is read.
In a situation where the image-forming apparatus uses an electrophotographic process, an electrostatic latent image is formed by previously charging a photosensitive drum with electricity and irradiating a surface of the photosensitive drum with a laser beam. The electrostatic latent image is developed into a toner image. The toner image is transferred onto and fixed to a sheet.
Here, to mount the above-described automatic document feeder on the image-forming apparatus body, the hinge unit is attached to the automatic document feeder, the automatic document feeder is lifted up such that the hinge unit is arranged at a lower position or that the automatic document feeder is standing, the hinge unit is temporarily fixed to an upper surface of the image-forming apparatus body, and then the hinge unit and the image-forming apparatus body are fastened by a screw (for example, see Japanese Unexamined Patent Application Publication No. 9-105266).
However, with this technique, it is still difficult to mount the automatic document feeder. Specifically, the automatic document feeder may weigh approximately 15 kg. Thus, it is difficult for it to stand without a support (in a self-standing state). In order to prevent the automatic document feeder from falling to the opposite side, a worker has to fasten the screw while another worker supports the automatic document feeder. When the above-described technique is used, a single worker can complete the attachment process. In this situation, however, the hinge unit is merely temporarily fixed to the upper surface of the image-forming apparatus body at one position. The worker has to fasten the screw with one hand while supporting the automatic document feeder with the other hand.
Even if the hinge unit is temporarily fixed to the upper surface of the image-forming apparatus body at a plurality of positions, when the positions are close to each other, the posture of the image-forming apparatus body may become unstable. Therefore, it is difficult to keep the automatic document feeder in a self-standing state.